Gravity fed vaporizing devices have been used for a wide range of vaporizing and watering purposes. As is pointed out in U.S. Pat. No. 3,254,841, such devices may be used to eliminate or cover up undesired scents, or to dispense volatile chemicals over extended periods of time, such as during pest control operations. Another application for such devices is described in U.S. Pat. No. 4,270,696, which describes a drip irrigator for watering plants. Further, such devices are commonly used as simple means for humidifying dry air.
The method of operation of such devices is generally as follows. An absorbent material, such as a towel or an absorbent wick is immersed in a liquid, or has liquid placed on it, so that a wicking or spreading effect occurs and the liquid moistens as much of the absorbent material as the user desires. Depending upon how much liquid is made available, the absorbent material can become entirely saturated. Natural or forced air flowing past the absorbent material causes the liquid to evaporate into the local atmosphere. Greater air flow and higher temperatures will cause faster evaporation of the liquid. Similarly, exposing more moistened surface area of the absorbent material to air speeds the introduction of evaporated material to the surrounding air. Unfortunately, whether for aesthetic reasons or because of space limitations, it is often not practical to use a large gravity fed humidifier in many circumstances and, as a consequence, the non-industrial application of such devices is often limited to quite small-scale uses such as room freshening and the like.
While such devices do not, as a general rule, introduce moisture into the air as quickly as devices such as steam humidifiers, they are also less dangerous in that there are not normally any electrical components capable of contacting water and there is no high temperature steam that might cause burns. Further, because of their relative simplicity, they are generally inexpensive to manufacture and sell, and easy to use.
It is desirable to provide an attractive, gravity fed humidifier in which a maximum amount of absorbent material can be exposed to dry air in a minimal amount of space while avoiding the dangers of other types of humidifiers.